Question

Are there any other spectroscopic techniques, other than UV-Visible spectroscopy, which might be able to distinguish between the cis- and trans-[Co(en)2Cl2]Cl diastereomers? For example, IR or 1H nmr? For those techniques, explain what you might expect to observe that would or would not assist you in assigned the stereo-chemistry of the green and violet isomers.

Answer 1

Both Infra-red and proton nmr spectroscopy are helpful in distinguishing between cis and trans isomers. They both provide proper differentiation between the two isomers. See hand written images for explaination.